Method of forming upon copper and copper alloys a layer protective against the corrosive action of sea-water.



ITED STATES PATENT OFFICE.

GUSTAV KURTH, OF BAUTZEN, GERMANY, ASSIGNOR T0 FIRM C. G. TIETZENS EIDAM,

OF BAUTZEN, GERMANY.

METHOD OF FORMING UPON COPPER AND COPPER ALLOYS A LAYER PROTECTIVE AGAINST THE CORROSIVE ACTION OF SEA-VTATER.

No Drawing.

To all "iv/"1 am. it may concern:

Be it known that I, GUSTAV KURTH, a citizen of. the German Empire, residing at A03 T alstrasse, Bautzen, in the Kingdom of b ony, Empire of Germany, have invented new and useful Improvements in Methods of Forming upon Copper and Copper Alloys a Layer Protective Against the Corrosive Action of Sea-Water, of which the following is a specification. I

The present invention relates to an improved method of forming upon copper and copper alloys a layer protective against the corrosive action of sea-water.

It is known to use iron as a protective means for copper and copper alloys against the corrosive action of sea-water. This protection has been used in the form of iron coils, wire-nettings, and the like or wire bodies, which in order to form a proper conductive connection were applied close upon the surfaces to be protected. Owing to the induced electrolytic action the iron originates a strong deposit of oxid of iron, and

after a certain time a layer of oxid of iron is formed on the copper or copper alloy surface, said layer acting as an insulator and in consequence thereof affording a protective action for said copper surface or the like. (Cf. Zeitschrift dcs Vereins Deutschen Ingenieure, 1905, page 735.) However, the iron coils, wire-nettings or other wire bodies cannot be intimately connected with or joined to the surface to be protected; and, when used, reduce to a great extent the free section of passage in the pipes or tubes to be protected, give rise only to a local protection, can only be set in place with great difficulty, and by breaking into large pieces obstruct or choke the obturators, or valves, thus decreasing the safety of operation. Moreover, should any of the broken-off pieces pass into the engine, serious damage might be produced. (Cf. Marine-Rundsckau, July 1912, page 926.) WVhile, it is quite true that nettings made of iron wire and the like or wire bodies form a more eificient covering of the surface to be protected than coils, whose windings are easily displaceable, such nettings, bodies or the like are not suited for general use, for example, for protecting bow-pipes or curved tubes.

The above named disadvantages, common Specification of Letters Patent.

Application filed May 22, 1915.

Patented Mar. 21, 1916.

Serial No. 29,746.

to all protectors of iron heretofore known, are avoided by my invention, which consists in forming upon the copper or copper alloy surfaces to be protected a layer of iron or steel filings distributed as regularly as possible upon said surfaces and firmly connected to the latter in a suitable manner. For example, the iron filings can be rolled or pressed upon said surfaces.

This method can be easily carried out and allows of the whole surface being evenly coated and connected with the protective material. As the filings rolled on or pressed on upon said surfaces have a large surface, a regular and strong oxid layer is formed upon the whole surface and local irregularities are avoided. Further, the formed layer does by no means prejudice the free section of passage of the tube or pipe and renders impossible the formation of great lumps of material, so that no danges of the obturators being choked exists. At the same time, the method forming the object of the present invention is only connected with small costs, because waste material can be used for obtaining the iron filings or particle-s.

The copper sheets or the like provided with the above described protective layer or coating may be used directly, or tubes or pipes may be formed with the same in the usual manner. The finished tubes can also be delivered for use in a ready oxidized condition, so that, after the tubes being inserted into the piping, no soiling of the water with oxid of iron is to be feared.

As trials have shown, iron or steel filings adhere very strongly to copper sheets. Alterations of form, warping or incandescence of the sheets exert no influence upon the durability of the connections.

I wish to be Well understood that, when in the present specification and claims I generally speak of copper, copper-alloys are meant as equivalents. Also iron and steel filings are both to be considered as equivalents.

What I claim and desire to secure by Letters Patent is:

1. A method of forming on copper surfaces a layer protective against the corrosive action of sea-water, consisting in distributing evenly on the surfaces to be protected.

iron filings and durably connecting said filings to said surfaces While cold.

A method of forming on copper surfaces a layer protective against the corrosive action of sea-water, consisting in firmly rolling oniron filings upon the surfaces While cold.

method of forming on copper surfaces a layer protective against the corrosive action of sea-Water, consisting in firmly pressing on iron filings upon the surface While cold.

4. A method of forming on copper surfaces a layer protective against the action of sea Water, consisting in distributing and at- Copies of this patent may be obtained for five cents each, by addressing the taching upon the surfaces to be protected separated iron filings.

5. A method of forming on copper surfaces a layer protective against the action of sea Water, consisting in distributing and attaching upon the surfaces to be protected iron filings and subjecting the filings and surfaces to electrolytic action.

In testimony whereof I have signed my name to this specification in the presence of tWo subscribing Witnesses.

GUSTAV KURTH. Witnesses:

CLARE SIMON,

BERTOLD A. BRAUN.

Commissioner of Patents,

Washington, D. C. 

